1. Field
One embodiment of the present invention relates to a technique of controlling a playback apparatus comprising a motion picture reproducing function, and more specifically to an image playback apparatus with an improved playback quality, and a control method employed in the apparatus.
2. Description of the Related Art
Recently, image playback apparatus which can play back highly definition images have been developed. In the decoding process of these high definition images, an enormous amount of data processing is required. Some playback apparatus do not involve a sufficient memory capacity or decoding process. For example, Jpn. Pat. Appln. KOKAI Publication No. 2006-115245 discloses a playback technique which can prevent the failure of the buffer and carry out playback while maintaining the synchronization of video and audio signals at a good level by switching a method of outputting data stream at a timing similar to the input timing upon start of the playback of TS from a recording medium and switch of a special playback and an ordinary playback, and a method of outputting data stream in reply to data request from a decoder during decoding operation.
However, in the motion picture playback apparatus disclosed in Jpn. Pat. Appln. KOKAI Publication No. 2006-115245, the size of input queue of the decoder is set based on an expected value from experience plus an allowance. Even if such setting is carried out, the buffer fails in some cases depending on the contents to be played back. Especially, the order of video data and audio data in a data stream is arbitrary, such a case possibly occurs in which one type of data overflows from the buffer while the other type of data lacks.